The goal of this proposal is to develop a prototype pathogen detection device which is simple and inexpensive, yet capable of rapid an sensitive analyses. The device consists of two parts. The first part is a cassette containing an array of immobilized oligonucleotides selected for their ability to hybridize specifically with nucleic acids (DNA or rRNA) of target pathogens of interest. The second part, an optical scanning fluorometer, allows target DNA hybridized to the immobilized oligonucleotides to be detected by using fluorescent nucleic acid-specific dyes. The configuration of the oligonucleotide array will permit rapid simultaneous screening for a variety of pathogens, with great sensitivity. The proposed work has three objectives: (a) to select specific oligonucleotide probes for three human fungal pathogens, (b) to determine the sensitivity and specificity of these probes for fungal pathogen detection in a prototype scanning fluorometer, and (c) to develop a reliable method for sample preparation for fungal analysis using the prototype device. The device is initially targeted to the detection of human fungal infections, but the method will lend itself equally well to the detection of other pathogenic micro organisms which are difficult to identify by means currently employed. PROPOSED COMMERCIAL APPLICATION: This technology has broad potential utility in low cost, sensitive, rapid detection of micro-organisms from a variety of sources. Applications include medical and veterinary diagnostics, agricultural seed certification, disease prevention in agronomy, and food and beverage quality control.